Graphical user interfaces (GUIS) provide ways for users of computers and other devices to effectively communicate with a computer. In GUIs, available applications and data sets are often represented by graphical images such as icons and windows which the user can directly manipulate and select, rather than have to manually type a command to initiate a program. Icons are on-screen symbols that simplify access to a program, command, or data file and are usually activated by moving a mouse-controlled cursor onto the icon and pressing a button or key.
GUIs include graphical images on computer monitors. A computer window is a portion of the graphical image that appears on the monitor and is dedicated to some specific purpose. Windows allow the user to treat the graphical images on the computer monitor like a desktop where various files can remain open simultaneously. The user can control the size, shape, and position of the windows.
Users of GUIs often would like to examine functions, applications, data, and other parameters for different periods of time. Currently this feature is not part of a standard GUI interface. However, by use of software that manages various file versions, for example the IBM High Performance Optical File System (HPOFS) with a novel GUI interface, access can now be gained to versions of functions, applications, databases, displayed information, files, etc. HPOFS stores versions of files, such as databases and application outputs, on write-once (WORM) optical media. A derivative of this file system could also be applied to Compact-Disk Recordable (CD-R) media, which is also write once. Write-once media cannot be overwritten, which makes it ideal for retaining unalterable versions of files. Alternately, versions of files can be stored on any other form of media, such as hard disk, magnetic or optical tape, floppy disk, magneto-optical (MO), phase-change (PC), CD-Erasable (CD-E), digital video/versatile disks (DVD), etc.